Wallboards, wallboard systems and methods for installing them

ABSTRACT

The present disclosure relates generally to wallboards, for example, suitable for use in constructing internal walls. The present disclosure relates more particularly to a wallboard and a method that provides simplified high-quality surface finishing. The wallboard includes a wall panel having a front surface and a rear surface. A sandable coating is disposed on the front surface of the wall panel. The method includes positioning wallboards adjacent to one another, applying sandable joint compound over joint formed between the wallboards, and sanding the joint compound and the sandable coating of the wallboards.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority of U.S. ProvisionalPatent Application No. 62/611,598, filed Dec. 29, 2017; U.S. ProvisionalPatent Application No. 62/612,369, filed Dec. 30, 2018; and U.S.Provisional Patent Application No. 62/651,102, filed Mar. 31, 2018, eachof which is hereby incorporated herein by reference in its entirety.

BACKGROUND OF THE DISCLOSURE 1. Field of the Disclosure

The present disclosure relates generally to wallboards, for example,suitable for use in constructing internal walls. The present disclosurerelates more particularly to a wallboard including a sandable coating ona front surface thereof.

2. Technical Background

Wallboards, for example gypsum wallboards that are commonly referred toas drywall, are often used to construct internal walls. The wall isframed with wooden or metal framing elements, such as studs, and thewallboards are hung on the frame using screws or other fasteners. Oncethe wallboards are hung, they provide a surface that forms the wall andis substantially flat. However, at the joints between adjacentwallboards and in the areas where the fasteners are inserted into thewallboards, the wall surface is not flat; these details cannot becovered over simply with paint.

In order to conceal the joints and fasteners, the wall is typically“finished” by covering the joints and fasteners with a joint compound.The finishing of the wall provides a uniformly smooth surface for paintor wall paper, so that the fasteners and the joints are not visible. Thetype of finish applied to the wall and the amount of effort used toachieve that finish can vary significantly based on the importance ofachieving a visibly uniform surface and the lighting on the wall.

When a high quality finish is desired to accommodate a certain type ofpaint or certain lighting, the process for finishing the wall can bevery laborious and require a skilled craftsman. For example, to achievea level 5 finish according to the standard set collectively by fivetrade associations (AWCI, CISCA, DWFC, PDCA and GA), the wall finishermust apply at least two coats of joint compound over flat joints, coverthe fasteners with joint compound, and apply a skim coat over the entirewall surface. In addition to applying the different layers of coating,the finisher must allow the coats to dry and sand away defects toproduce a smooth, monolithic surface. The finished wall must be smoothand free of tool marks or ridges. The process is expensive and takesmultiple days to complete. In addition, the process is artisanal andrequires skill to avoid unsightly defects.

What is needed is a wallboard that allows a high quality finish to beachieved more efficiently and with less expertise.

SUMMARY OF THE DISCLOSURE

In one aspect, the present disclosure provides a wallboard enablingsimplified high-quality surface finishing, comprising:

-   -   a wall panel including a front surface, a rear surface, and        opposing first and second side edges; and    -   a sandable coating disposed on the front surface of the wall        panel.

In another aspect, the disclosure provides a system enablinghigh-quality surface finishing of wallboards, the system comprising:

-   -   at least two wallboards each including        -   a wall panel having a front surface, a rear surface, and            opposing first and second side edges, and        -   a sandable coating disposed on the front surface of the wall            panel; and    -   a sandable joint compound configured to cover a joint between        the at least two wallboards.

In another aspect, the disclosure provides a method of forming a highquality finish on a wall surface, the method comprising:

-   -   providing first and second wallboards each including        -   a wall panel having a front surface, a rear surface, and            opposing first and second side edges, and        -   a sandable coating disposed on the front surface of the wall            panel;    -   positioning the first wallboard adjacent to the second wallboard        so as to form a wall surface with a joint between the first and        second wallboards;    -   applying a mass of sandable joint compound over the joint, the        mass of joint compound extending at least from the coating of        the first wallboard to the coating of the second wallboard; and    -   sanding at least a portion of the coating of the first        wallboard, at least a portion of the coating of the second        wallboard, and the joint compound so as to form the high quality        finish on the wall surface.

In one aspect, the present disclosure provides a method for making awallboard enabling simplified high-quality surface finishing,comprising:

-   -   providing a wall panel including a front surface, a rear        surface, and opposing first and second side edges; and    -   forming a sandable coating disposed on the front surface of the        wall panel.

Additional aspects of the disclosure will be evident from the disclosureherein.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the methods and devices of the disclosure, and areincorporated in and constitute a part of this specification. Thedrawings are not necessarily to scale, and sizes of various elements maybe distorted for clarity. The drawings illustrate one or moreembodiment(s) of the disclosure, and together with the description serveto explain the principles and operation of the disclosure.

FIG. 1 is a schematic perspective view of a wallboard according to oneembodiment of the disclosure;

FIG. 2 is a schematic cross sectional side view of the wallboard of FIG.1;

FIG. 3 is a schematic cross sectional side view of a wallboard accordingto another embodiment of the disclosure;

FIG. 4 is a schematic perspective view of a system including wallboardsof FIGS. 1 and 2 according to one embodiment of the disclosure; and

FIGS. 5A, 5B, 5C, 5D, 5E and 5F are schematic views of a process offorming a high-quality wall finish according to one embodiment of thedisclosure.

FIG. 6 is a cross-sectional view of a wall assembly according to oneembodiment of the disclosure.

FIG. 7 is a cross-sectional view of a wall assembly according to anotherembodiment of the disclosure.

DETAILED DESCRIPTION

As described above, the present inventors have noted that theconventional process for creating a high quality finish of wallboard istime consuming and costly. Accordingly, one aspect of the disclosure isa wallboard including a wall panel and a sandable coating on a frontsurface of the wall panel. Such a wallboard is shown in a schematicperspective view in FIG. 1 and in a schematic cross sectional side viewin FIG. 2. Wallboard 100 includes a wall panel 110 having a frontsurface 112, a rear surface 114 and opposing first and second side edges116, 118. A sandable coating 140 is disposed on the front surface 112 ofthe wall panel 110.

The person of ordinary skill in the art will appreciate that the wallpanel can have a variety of different constructions. In certainembodiments of the wallboards as otherwise described herein, the wallpanel includes a core that is covered by a facing, e.g., in the form ofa sheet. In other embodiments, the wall panel is made without a facingdisposed between a core and the sandable coating. As the person ofordinary skill in the art will appreciate, facings can be disposed onboth the front surface and the rear surface of the core, or only on oneor the other. Facings can extend onto the first and/or second sideedges, as will be apparent to the person of ordinary skill in the art.For example, in the embodiment of FIGS. 1 and 2, facing 122 is disposedon the front and rear surfaces, and on both side edges of the core(i.e., generally at surfaces 112 and 114 and edges 116 and 118 of thewall panel).

The person of ordinary skill in the art will appreciate that the core ofa wall panel as described herein can be formed of a variety ofmaterials. In certain embodiments, the core of the wall panel is formedfrom a gypsum plaster. In other embodiments, the core of the wall panelis formed from a struvite-K/syngenite plaster, such as a materialdescribed in International Patent Application Publication no.2015/057732, which is hereby incorporated herein by reference in itsentireties. Various additional materials suitable for use as a core ofthe wall panel include concrete, fiber-reinforced materials, foamedpolymeric materials such as foamed polystyrene, mineral board materials,mineral fiber board materials, cellulosic materials, particle boardmaterials, oriented strand board materials, or a combination thereof. Ofcourse, the person of ordinary skill in the art will appreciate thatother suitable materials may be used. The core can include a variety offillers and additives, as the person of ordinary skill in the art willappreciate. For example, in some embodiments, the core may include oneor more fillers, for example, selected from calcium carbonate, starch,sand, ceramic microspheres, perlite, foam, fibers, fly ash, slag, orcellulosic fillers, including wood particles and fibers. Similarly, insome embodiments, the core may include one or more additives includingaccelerators to increase the setting time, such as BMA or potash, waterresistance, such as wax or silicone, sugars, retarders, cellulosicfibers, fiberglass fibers, boric acid, fire resistance, such asvermiculite, or other additives as the person of ordinary skill in theart will appreciate. The person of ordinary skill in the art will selectfiller(s) and/or additive(s) based on the particular core material andthe particular properties desired for the overall wallboard.

Similarly, the person of ordinary skill in the art will appreciate thata variety of materials can be used as the facing(s). For example, incertain embodiments, the facing is made of paper, a fiberglass mat, or apolymer sheet. Other facing materials may alternatively be used, as willbe appreciated by a person of ordinary skill in the art.

In certain embodiments as otherwise described herein, the wall panel andcorresponding wallboard may be in the shape of a rectangle, where thefirst and second side edges 116, 118 extend from a first end 124 to asecond end 126. In many embodiments the length of the wall panel fromend to end is longer than the width of the wall panel from side to side.In certain embodiments as otherwise described herein, the length of thewall panel 110 from the first end 124 to the second end 126, and thecorresponding length of the wallboard 100, is in a range of 6 feet to 20feet, or in a range of 8 feet to 16 feet, for example, 8 feet, 9 feet,10 feet, 12 feet, 14 feet, or 16 feet. In certain embodiments asotherwise described herein, the width of the wall panel 110 from thefirst side edge 116 to the second side edge 118, and the correspondingwidth of the wallboard 100, is in a range of 36 to 72 inches, forexample 48 inches or 54 inches. While the embodiment of wallboard 100 isshown as a rectangle, in other embodiments, the wall panel may have adifferent shape, such as a triangular or round panel, where the sideedges are those edges that are generally opposed to one another.

The thickness of the wall panel and corresponding wallboard may also beselected for various design constraints as will be appreciated by aperson of ordinary skill in the art. In certain embodiments as otherwisedescribed herein, the thickness of the wallboard 100 is in a range of ⅛inch to 1.5 inches, or in a range of ¼ inch to 1.25 inches. In certainembodiments as otherwise described herein, the thickness of the wallpanel 110 is of a size commonly used in construction materials, such as¼ inch, ½ inch, ¾ inch or 1 inch and the sandable coating adds to theoverall thickness of the wallboard 100 from that size. In otherembodiments, the wall panel 110 may be of a size that is slightlyreduced from commonly used dimensions, so that the overall thickness ofthe wallboard has a size that is commonly used in constructionmaterials. For example, the combination of the wall panel and sandablecoating may have a thickness of ¼ inch, ½ inch, ¾ inch or 1 inch.

In certain embodiments as otherwise described herein, the wall panel hasat least one tapered portion that extends from a respective one of theside edges. For example, in the embodiment of FIG. 1, the wall panel 110has a tapered portion 128 at the first side edge 116 and a taperedportion 128 at the second side edge 118. In certain embodiments asotherwise described herein, the tapered portion 128 is formed by aslight slope of the front surface 112 from an inner border 130 of thetapered portion 128 toward the rear surface 114. In contrast, the rearsurface 114 may be flat, and the taper may be provided entirely by thefront surface 112. In certain embodiments, the tapered portion 128 maybe formed by a short bevel at the corresponding edge 116, 118 of thewall panel 110, or in other embodiments the tapered portion may beformed by a longer taper of the thickness of the wall panel.

In certain embodiments as otherwise described herein, the taperedportion 128 extends at least 1 inch, e.g., at least 2 inches, from therespective side edge of the wall panel 110. And in certain embodimentsas otherwise described herein, the tapered portion extends no more than5 inches, e.g., no more than 3 inches from the respective side edge ofthe wall panel. For example, in certain such embodiments, the taperedportion 128 may extend from the side edge in a range of 1 to 5 inches,or in a range of 1 to 3 inches, or in a range of 2 to 3 inches, or in arange of 2 to 2.5 inches, for example 2.25 inches.

In certain embodiments as otherwise described herein, the depth of thetaper (i.e., in the direction of the thickness of the wallboard) is in arange of 0.02 inches to 0.25 inches from the front surface of the wallpanel. In some embodiments the taper is in a range of 0.03 inches to0.15 inches, or in a range of 0.03 inches to 0.09 inches, for example,about 0.05 inches. In certain embodiments as otherwise described herein,the depth of the taper is in a range of 5% to 50% of a thickness of theboard, e.g., in a range of 10% to 25%. In some embodiments, the edges atthe ends 124, 126 of the wall panel are also tapered, such that the wallpanel 110 is tapered on all four sides.

It should be understood that the sandable coating 140 is applied to thewall panel 110 before the wallboard 100 is installed on a wall frame orotherwise disposed on a wall; for example, the sandable coating 140 maybe applied by a manufacturer. The sandable coating can be applied, e.g.,by the manufacturer of the wall panel as a step in its manufacturingprocess, or by a separate manufacturer (e.g., starting with aconventional wall panel and applying and shaping the sandable coating ina separate manufacturing process). Notably, the wallboard with thesandable coating can be delivered to a jobsite, ready for the installerto use. Thus, the wallboard 100 includes the sandable coating 140 whilethe wallboard 100 is still free of any fasteners, such as screws oradhesive, that hold the wallboard to a wall frame. This differs from aconventional skim coat, which is only applied after the wallboard isattached to the wall frame. Accordingly, another embodiment of thedisclosure is a wallboard as described herein, not installed on astructure such as a building or wall.

The term sandable coating, as used herein, refers to a coating that iscapable of being smoothed by removal of small amounts of the coatingwithout damaging the underlying board. In particular the sandablecoating can be sanded without burring or marring of any underlying paperfacing of the wall panel. Furthermore, the sandable coating allows fortargeted removal using conventional sanding techniques without damage tothe wall, which may result if the coating were too easily removable. Forexample, a softer coating might be susceptible to scratching or denting.

In certain embodiments as otherwise described herein, the sandablecoating has a particular removal rate as determined by a sandabilitytest. The sandability test includes applying the coating to a ½ inchplastic platen that includes 2 mm shims and air drying the coating to aconstant weight. The platen is weighed and then mounted on a GardnerAbrasion and Washability/Scrubability Tester. The sanding block of thetester is lined with 150 grit sandpaper which is placed on the surfaceof the coating. After 25 cycles of running the sanding block over thesurface of the coating, dust is removed and the sample of coating isweighed once again. In certain embodiments, using the described test,the sandable coating is removed at a rate of no more than 2 grams per150 cm², e.g., no more than 1 gram per 150 cm², e.g., no more than 0.7grams per 150 cm².

The person of ordinary skill in the art will appreciate that a varietyof materials can be used as the sandable coating. As used herein, asandable coating is one that is sandable using sandpaper, sandingblocks, an electric sander, or other structure as will be appreciated bya person of ordinary skill in the art. For example, the sandable coatingis sandable with 150 grit sandpaper. A variety of conventional materialscan be used to provide the sandable coating, including materialsconventionally used as skim coatings or joint compounds in wallboardinstallations. For example, the coating can be highly filled polymer(e.g., a highly-filled acrylic), a cement-based composition, or aplaster composition. One embodiment of the sandable coating is ExtremeAll Purpose Joint Compound (CertainTeed Gypsum, Inc, Malvern, Pa.).

In certain embodiments, the sandable coating can provide additionalfunctionality, for example, by including one or more functionalcomponents to provide a desired function to the coating. For example, incertain embodiments, the sandable coating includes an antimicrobialcomponent or an antimold component, such as a pyrithone salt (e.g., zincpyrithone, sodium pyrithone), 2-octyl-2H-isothiazol-3-one, carbendazim,terbutryn, 3-iodo-2-propynylbutylcarbamate, propiconazole,2-[(thiocyanatomethyl)thio]benzothiazole, 2-(4′-thiazolyl)benzimidazole,10,10′-oxybisphenoxyarsine, N-(fluorodichloromethylthio)phthalimide,N-dimethyl-N′-phenyl-(N′-fluorodichloromethylthio) sulfamide, or diuron.Of course, other antimicrobial/antimold components can also be used. Incertain embodiments, the sandable coating includes a photocatalyst,e.g., particulate titania (including n-doped mesoporous titania), zincoxide, and bismuth-containing materials such as Bi₂O₃, BiVO₄, Bi₂WO₆ andBi₅O₇I/Bi₂O₃, which can provide photocatalytic reduction of a variety ofspecies, e.g., oxides of nitrogen. In certain embodiments, the sandablecoating includes a formaldehyde scavenger, e.g., alkali metabisulfite,alkali bisulfite, alkali sulfite, alkali thiosulfate, urea, ethylacetoacetate, carbodiimide compounds, a low mole ratiomelamine-urea-formaldehyde resin composition, or materials availableunder the tradename AGOCHEM® SAM. In certain embodiments, the sandablecoating includes a fragrance. In certain embodiments, the sandablecoating includes an intumescent system (e.g., a carbon source such aspolyvinylalcohol, pentaerythritol or dierythritol, a blowing agent suchas melamine or an HCl-releasing polymer or additive, and an acidcatalyst such as ammonium polyphosphate), The person of ordinary skillin the art will select effective amounts of such components to providethe desired function and to be compatible with the sandable coating.

The sandable coating can be applied to the wall panel in a variety ofmanners, as will be apparent to the person of ordinary skill in the art.For example, in certain embodiments the sandable coating is applied tothe wall panel by roll coating. In other embodiments, the coating isapplied by spraying or by curtain coating.

In certain embodiments as otherwise described herein, the sandablecoating 140 includes a main portion 142 that covers a majority of thefront surface of the wall panel and has a thickness of at least 0.4 mm.In certain such embodiments, the main portion of the coating has athickness of no more than 5 mm, e.g., no more than 3 mm. The mainportion 142 of the coating 140 may be of substantially uniformthickness, for example varying no more than 0.1 mm from the average. Incertain embodiments, the main portion 142 of the coating 140 may have athickness in a range of 0.4 mm to 2 mm, or in a range of 0.5 mm to 1.5mm, or in a range of 0.6 mm to 1.2 mm, for example, about 1 mm.

In certain embodiments as otherwise described herein, the coating 140includes an area of reduced thickness 144 in a vicinity of at least oneof the side edges 116, 118. In contrast to the main portion 142 of thesandable coating 140, the area of reduced thickness 144 has a thinnercoating. As used herein, the term “in a vicinity” means within 8 inches.Thus, in certain embodiments the area of reduced thickness is confinedto a section of the wallboard 100 that is no more than 8 inches from theside edges. It is also possible that the area of reduced thickness be inthe vicinity of the edges at the ends 124, 126 of the wallboard 100. Asdescribed in more detail below, the area of reduced thickness 144 mayinclude no coating at all, thereby forming an uncovered region on thefront of the wall panel 110. In other embodiments, the main portion ofthe coating may extend all the way to the side edges 116, 118. On theother hand, the area of reduced thickness 144 may be provided in avicinity of the edges at the ends 124, 126 of the wallboard 100.

In certain embodiments as otherwise described herein, the area ofreduced thickness 144 extends at least 1.5 inches from the respectiveside edge 116 or 118. Likewise, in certain such embodiments, the mainportion 142 of the coating 140 extends no closer to the edges than 1.5inches. In some embodiments, the area of reduced thickness extends fromthe respective side edge 116 or 118 a distance in a range of 1 inch to 6inches, or in a range of 1 inch to 4 inches, or in a range of 2 inchesto 3 inches, for example about 2.25 inches or about 2.5 inches.

In certain embodiments as otherwise described herein, the area ofreduced thickness 144 includes a tapered section 146 of the coating. Thetapered section 146 of the coating has a gradual reduction in thecoating thickness from the main portion 142 to the respective side edge116, 118, or to a point where the coating ends and the wall panel isleft uncovered. The tapered section 146 of the coating may taper over adistance in a range of 1 inch to 4 inches, or in a range of 1 inch to 3inches, for example about 2 inches.

In certain embodiments as otherwise described herein, the coatingincludes a smooth transition between the area of reduced thickness 146and the main portion 142. For example, the reduction in the thickness ofthe coating 140 in the area of reduced thickness 146 begins verygradually so that the edge of the area of reduced thickness is notprominent and is not visible by a person. In some embodiments, the areaof reduced thickness of the coating may be aligned with thecorresponding tapered portion of the wall panel. In certain embodiments,the wall panel includes a tapered portion extending from a respectiveone of the side edges, and wherein the area of reduced thickness extendsto within 1 inch from an inner border of the tapered portion of the wallpanel. For example, wall panel 120 includes a tapered portion 128 thatextends from a respective side edge 116, and the area of reducedthickness 146 extends to within 1 inch from an inner border 130 of thetapered portion 128 of the wall panel 120.

Another embodiment of a wallboard having a smooth transition of the mainportion of the coating to the area of reduced thickness is illustratedin schematic cross-sectional side view in FIG. 3. Wallboard 200 includesa wall panel 210 with a front surface 212, a rear surface 214, a firstside edge 216 and a second side edge 218. At each of the first andsecond side edges 216, 218, the wall panel 210 includes a taperedportion 218. The wallboard 200 also includes a sandable coating 240disposed on the front surface 212 of the wall panel 210. Compared to thecoating 140 in FIGS. 1 and 2, the thickness of coating 240 is reducedover a much smaller distance. Still, the transition from the mainportion of the coating to the area of reduced thickness remains smooth,as the coating edge 248 is rounded. In some embodiments the coating edge248 is disposed within 1 inch of the inner border 230 of the taperedportion 228 of the wall panel. Indeed, coating edge 248 may be disposedat the inner border 230 of tapered portion 228, as shown in FIG. 3.

In certain embodiments as otherwise described herein, the coating edge248 is set back from the respective side edge 216 so as to form anuncovered portion 250 of the wall panel between the coating edge 248 andthe respective side edge 216. The uncovered portion 250 allows a workerto hang the wallboard 200 with fasteners without having to insert thefasteners through the coating 240. Further, as described in more detailbelow, having the coating edge 248 set back from the side edge 216allows the worker to use the coating edge 248 as a guide when placingjoint compound over a joint between two adjacent wallboards.Specifically, the worker may be guided by the coating edge 248 to applythe joint compound only over the uncovered portion 250 of the wallboard200.

In certain embodiments as otherwise described herein, the uncoveredportion 250 extends at least 1 inch, e.g., at least 2 inches, from therespective side edge 216. In certain embodiments as otherwise describedherein, the uncovered portion extends no more than 5 inches, e.g., nomore than 3 inches, from the respective side edge. In certainembodiments, the uncovered portion extends in the range of 1 to 5inches, for example 2 inches to 3 inches, from the respective side edge.In some embodiments, if the wall panel 210 includes a tapered portion228, the uncovered portion 250 may coextend with the tapered portion 228of the wall panel. For example, the coating edge 248 that defines theuncovered portion 250 may be located within ¼ inch from the inner border230 of the tapered portion 228.

In certain embodiments as otherwise described herein, an uncoveredportion may be included at both the side edges and the end edges of thewallboard. In other embodiments as otherwise described herein, thecoating extends from the first end of the wall panel to the second endof the wall panel. Accordingly, in such cases the wallboard does notinclude an uncovered portion at either end of the wall panel.

Another aspect of the disclosure is a system that simplifieshigh-quality surface finishing of wallboards. Such a system is shown inschematic view in FIG. 4. System 300 includes at least two wallboards asdescribed herein, and a sandable joint compound 360 configured to covera joint between the at least two wallboards. Specifically, theillustrated system 300 includes two wallboards 100 (e.g., according toFIGS. 1 and/or 2 described above), disposed adjacent to one another toform a joint 355 therebetween, and a joint compound 360 covering aportion of the joint 354. Of course, the system may include wallboardsaccording to other embodiments of the disclosure, and may include morethan two. Further, the system may include the wallboards before they areinstalled next to one another. For example, the wallboards of the systemmay be in a stack ready for installation. Likewise, the system mayinclude the joint compound before it is applied over the joint. Forexample, the joint compound may be in a container. In this regard, thejoint compound of the system may be in the form of a wet paste, or itmay be in the form of a powder that is mixed with a liquid such as waterbefore it is applied over the joint.

In certain embodiments as otherwise described herein, the joint compoundis used both to embed tape in the joint, and is also used to provide asurface of the finished wall (e.g., a surface that becomes substantiallycoplanar with the coating). In other embodiments, the joint compound mayact as a topping compound that is used in conjunction with a tapingcompound. For example, a taping compound may be used to embed jointreinforcement tape within the joint between wallboards, and then thejoint compound 360 of system 300 may be applied over the taping compoundand the tape embedded therein. In this way, the joint compound 360 mayprovide desired visual characteristics as described below, but may beused with other compounds that stabilize the joint reinforcement tape.

In certain embodiments as otherwise described herein, a composition ofthe coating 140 of the wallboards is substantially the same as acomposition of the joint compound 360 (i.e., on a dry solids basis, ascured). As will be appreciated by those of ordinary skill in the art,the characterization of the compositions of the coating 140 and jointcompound 360 as being the same excludes the water content of thecompositions, particularly when the joint compound is a wet paste readyto be applied to the joint. However, the solid components of the coating140 and joint compound 360 may be the same.

The person of ordinary skill in the art will appreciate that a varietyof materials can be used as the joint compound. The joint compound isdesirably sandable, and is desirably similarly sandable to the coating.A variety of conventional materials can be used to provide the jointcompound, including materials conventionally used as joint compounds inwallboard installations. For example, the joint compounds can be highlyfilled polymer (e.g., a highly-filled acrylic), a cement-basedcomposition, or a plaster composition. Any desirable weight can be used.Specific embodiments of the joint compound include One All-Purpose JointCompound (CertainTeed Gypsum, Inc), Extreme All Purpose Joint Compound(CertainTeed Gypsum, Inc.), Plus 3® Joint Compound (USG, Chicago, Ill.),and Rapid Coat (Continental Building Products, Herndon, Va.), SheetrockAll Purpose (USG) or All-Purpose material available from NationalGypsum. The joint compounds can be applied to the wall panel in avariety of manners, as will be apparent to the person of ordinary skillin the art, for example, using a trowel or a putty knife. The jointcompounds can alternatively be applied using a drywall compound flat boxor an automatic drywall taper.

In certain embodiments as otherwise described herein, the coating 140 ofthe wallboards 100 has at least one visual characteristic that matches avisual characteristic of the joint compound 360. The matching of visualcharacteristics as described herein includes values of a correspondingparameter measuring the visual characteristic that are close enough toone another that any distinction is not perceivable by a human eye.Likewise, a parameter that directly measures a difference between visualcharacteristics may be so small that a person cannot perceive adistinction between the surfaces, and as such the visual characteristicswould be considered to match.

In certain embodiments as otherwise described herein, the visualcharacteristic is gloss. Variations in gloss along a wall areparticularly noticeable because the visibility of gloss changes atdifferent angles. In many circumstances, such as hallways, people viewwalls over a wide range of angles. For example, while walking along awall, the far portions of the wall are viewed at nearly 90 degrees (fromthe normal vector of the wall surface) while the nearest portion of thewall is viewed at 0 degrees. Accordingly, differences in gloss can behighly noticeable.

Gloss is quantified in gloss units measured at a certain angle, with theangle being selected depending on the level of gloss, to provide a glossmeasurement with a relatively low uncertainty. As used herein, thephrase “difference in gloss” refers to a difference in the gloss valuesof two surfaces measured at 60 degrees if both of the values are in arange from 10 gloss units to 70 gloss units when measured at that angle.If the gloss value of either surface when measured at 60 degrees isbelow 10, the phrase “difference in gloss” refers to the difference inthe gloss value of the two surfaces when measured at 85 degrees.Likewise, if the gloss value of either surface when measured at 60degrees is above 70, the phrase “difference in gloss” refers to thedifference in the gloss value of the two surfaces when measured at 20degrees.

In certain embodiments, the difference in gloss between the coating 140and the joint compound 360 is no more than 15 gloss units, e.g., no morethan 10 gloss units, e.g., no more than 5 gloss units, e.g., no morethan 2 gloss units.

Further, the perception of differences in gloss varies depending onwhether the surface has a higher gloss level or is more matte. At highgloss values (where the surface is very glossy) and at low values (wherethe surface is very matte), small changes in gloss are more noticeable.Thus, in certain embodiments as otherwise described herein, where thegloss value of either of two surfaces when measured at 60 degrees isoutside of a range from 20 gloss units to 70 gloss units, the differencein gloss between the coating 140 and the joint compound 360 is no morethan 5 gloss units, e.g., no more than 3 gloss units, e.g., no more than2 gloss units.

In certain embodiments as otherwise described herein, the visualcharacteristic is surface texture. In some embodiments, a difference inthe measure of surface roughness in Ra of the coating is 140 and thejoint compound 360 is no more than 20%, or no more than 10%. In someembodiments, the difference in surface roughness of the coating 140 andthe joint compound is no more than 2 Ra (μm), or no more than 0.4 Ra(μm), or no more than 0.2 Ra (μm).

In certain embodiments as otherwise described herein, the visualcharacteristic is color. In some embodiments, the color differencebetween the coating 140 and the joint compound 360 as measured by theCIELAB ΔE* parameter is no more than 3, or no more than 2.3, or no morethan 2, or no more than 1.

Examples of the small differences in visual characteristics provided bycertain embodiments of the wallboard are set out below, with referenceto differences in surface roughness and gloss.

In certain embodiments as otherwise described herein, the at least twowallboards are adjacent and form a joint therebetween, and the sandablejoint compound covers the joint and a portion of the sandable coating ofeach of the wallboards. In other words, in some embodiments, the system300 includes the wallboards 100 and joint compound 360 assembled, forexample on a wall. In such an installation of the system 300, a first ofthe wallboards 100 is adjacent to a second of the wallboards 100 andforms joint 354 therebetween. The joint compound 360 is disposed overthe joint 354 and at least a portion of the coating 140 of each of thewallboards 100. For example, the joint compound 360 may cover thetapered section 146 of the coating 140.

In certain embodiments as otherwise described herein the system furtherincludes a coating of paint 370 covering the coating 140 on thewallboards 100 and the joint compound 360. The coating of paint 370 hasa first section 372 that covers the coating 140 on the wallboards and asecond section 374 that covers the joint compound 360. At least onevisual characteristic of the first section 372 of the coating of paint370 matches a visual characteristic of the second section 374 of thecoating of paint 370.

In certain embodiments as otherwise described herein, the matchingvisual characteristic of the first and second sections of the coating ofpaint is gloss. In some embodiments, the difference in gloss between thefirst section 372 of the coating of paint and the second section 374 ofthe coating of paint is no more than 15 gloss units, e.g., no more than5 gloss units, e.g., no more than 2 gloss unit. Again, the perception ofdifferences in gloss units varies depending on whether the surface has ahigher gloss level or is more matte. Therefore, in certain embodimentsas otherwise described herein, where the gloss of the coating of paintmeasured at 60 degrees is less than 20 gloss units or more than 70 glossunits, the difference in gloss between the first section 372 of thecoating of paint and the second section 374 of the coating of paint isno more than 5 gloss units, e.g., no more than 2 gloss units

In certain embodiments as otherwise described herein, the matchingvisual characteristic of the first and second sections of the coating ofpaint is surface roughness. In some embodiments, a difference in themeasure of surface roughness in Ra between the first section 372 of thecoating of paint and the second section 374 of the coating of paint isno more than 20%, or no more than 10%. In some embodiments, thedifference in surface roughness (Ra) between the first section 372 ofthe coating of paint and the second section 374 of the coating of paintis no more than 1 μm, or no more than 0.2 μm, or no more than 0.1 μm.

In certain embodiments as otherwise described herein, the matchingvisual characteristic of the first and second sections of the coating ofpaint is color. In some embodiments, the color difference between thefirst section 372 of the coating of paint and the second section 374 ofthe coating of paint has a CIELAB ΔE* value of no more than 3, or nomore than 2.3, or no more than 2, or no more than 1.

The person of ordinary skill in the art will appreciate that while thewallboards described herein can be especially suitable for use asvertically-installed surfaces of buildings, they can also be used in avariety of other contexts, e.g., to define a ceiling. As used herein,the terms “wallboard,” and “wall” are understood not to requireverticality, but instead encompass uses as ceilings other places wherebuilding boards are used.

Another aspect of the present disclosure is a method of forming a highquality finish on a wall surface. The method may be understood withreference to FIGS. 5A to 5F. The method includes providing first andsecond wallboards 500, 502 and positioning the first wallboard 500adjacent to the second wallboard 502 so as to form a wall surface 556with a joint 554 between the first and second wallboards 500, 502. Amass of sandable joint compound 560 is applied over the joint (FIG. 5D).The mass of joint compound 560 extends at least from the coating 540 ofthe first wallboard 500 to the coating 540 of the second wallboard 502.The method also includes sanding at least a portion of the coating 540of the first wallboard 500, at least a portion of the coating 540 of thesecond wallboard 502, and the joint compound 560 so as to form a highquality finish on the wall surface 556.

In certain embodiments as otherwise described herein, applying the massof joint compound 560 over the joint includes applying a first layer 562of joint compound over the joint 554, embedding joint reinforcement tape566 in the first layer 562 of joint compound, drying the first layer 562of joint compound with the joint reinforcement tape 566 embeddedtherein, and applying a second layer 564 of joint compound over thefirst layer 562 of joint compound. FIG. 5B illustrates the jointreinforcement tape 566 embedded in the first layer 562 of the jointcompound and FIG. 5B shows the joint after the second layer 564 of jointcompound has been applied over the first layer 562. Alternatively, adifferent compound may be used to embed the joint reinforcement tape 566into the joint. For example, a layer of taping compound may be used toembed the joint reinforcement tape at the joint and the joint compound560 may serve as a topping compound applied as a subsequent layer. Aswill be understood by those of ordinary skill in the art, any suitablejoint reinforcement tape may be used with the present disclosure, forexample paper tape or fiberglass tape. As set forth herein, the act ofdrying the joint compound may be actively carried out or it may bepassive. Thus, the drying of the joint compound may include theapplication of forced air circulation and/or heat. Alternatively,allowing the joint compound to dry over time also constitutes a step ofdrying the joint compound.

In certain embodiments as otherwise described herein, the sanding of theportion of the coating of the first wallboard, the portion of thecoating of the second wallboard, and the joint compound reduces anyprotrusion or depression in the wall surface at the joint to no greaterthan 2 mm, or to no greater than 1 mm, or to no greater than 0.5 mm. Forexample, if there is a protrusion in an area of the joint, it may besanded down to be no greater than 0.5 mm. Likewise, if there is anindentation in the area of the joint the surrounded surface may besanded down so that the indentation is no greater than 0.5 mm.

In certain embodiments as otherwise described herein, the applying ofthe mass of joint compound forms a bump 568 (FIG. 5C) over the joint 554that projects further outward from the wall surface 556 than thecoatings 540 on the first and second wallboards 500, 502. The sanding ofthe joint compound 560 may remove the bump 568 (FIG. 5D).

In certain embodiments as otherwise described herein, the positioning ofthe first wallboard 500 adjacent to the second wallboard 502 includesplacing a first side edge 516 of the first wallboard 500 adjacent to asecond side edge 518 of the second wallboard 502. On the other hand, insome embodiments, an end of the first wallboard 500 is positionedadjacent to an end of the second wallboard 502.

In certain embodiments as otherwise described herein, the coating of thefirst wallboard includes an area of reduced thickness 544 in a vicinityof the first side edge 516, and the application of the joint compoundcovers at least a portion of the area of reduced thickness. For example,in FIG. 5C, the second layer 564 of joint compound covers the area ofreduced thickness 544 of the coating 540.

In certain embodiments as otherwise described herein, the coating 540 onthe first wallboard 500 includes a coating edge 548 in a vicinity of thefirst side edge 516 so as to form an uncovered portion 550 between thecoating edge 548 and the first side edge 516. The applying of the jointcompound may include using the coating edge 548 as a guide forrestricting the application of the joint compound 560 to the uncoveredportion 550 of the wallboard. For example, when applying the jointcompound to the joint, the worker may gather the joint compound onto ataping or joint knife, and then position the knife in the joint based onthe coating edge 548, so that the joint compound is applied only withinthe uncovered portion of the joint.

In certain embodiments as otherwise described herein, the joint compound540 may extend all the way up to an edge of the wall panel 510, as shownin FIG. 5E. In some embodiments, the method may include, before applyingthe joint compound 560, removing a portion 580 of the coating 540 of atleast the first wallboard in a vicinity of the joint. The applying ofthe joint compound may then include covering an area where the portion580 of coating is removed. In some embodiments, the portion of coatingis removed by sanding. Other tools may also be used to remove theportion of coating, as will be appreciated by those of ordinary skill inthe art.

In certain embodiments as otherwise described herein, the joint compound540 may extend up to an edge at an end 524 of the wall panel 510, andthe positioning of the first wallboard adjacent to the second wallboardincludes placing a first end 524 of the first wallboard 500 adjacent toa second end of the second wallboard 502. In some embodiments, theremoving of a portion of the coating 580 of at least the first wallboard500 includes removing coating at the first end 524 of the firstwallboard.

In another aspect, the present disclosure provides a method for making awallboard enabling simplified high-quality surface finishing. The methodincludes providing a wall panel including a front surface, a rearsurface, and opposing first and second side edges; and forming asandable coating disposed on the front surface of the wall panel. Thewall panel can be made using conventional techniques, and in any of avariety of forms as described herein. Moreover, the person of ordinaryskill in the art can, based on the disclosure herein, form a sandablecoating of a desired low surface roughness and desired color on asurface of the wall panel. Notably, the sandable coating can be formedin a manufacturing process that is remote from the site where thewallboard is to be installed (i.e., not on or adjacent the propertywhere the wallboard is to be installed). For example, the sandablecoating can be formed on the wall panel the manufacturer of the wallpanel as a step in its manufacturing process, or by a separatemanufacturer (e.g., starting with a conventional wall panel and applyingand shaping the sandable coating in a separate manufacturing process).Wallboards of the disclosure can then be delivered to the jobsite forinstallation as described herein.

Similarly, one or more wallboards of the disclosure can be fabricatedinto a building assembly (e.g., for use as a section of a wall, asection of a ceiling, or as some other building component). An exampleof such a wall assembly is shown in cross-sectional view in FIG. 6.Building assembly 650 includes framing or structural members 655 (e.g.,wooden 2×4s, or metal rails, wooden studs, metal studs, or channels), towhich sheathing 660 and two wallboards of the disclosure 600 and 601 areattached on opposing sides thereof. Another example is shown in FIG. 7,in which building assembly 750 includes framing members 755, to which awallboard of the disclosure 700 and 701 is attached on each opposingside thereof. As the person of ordinary skill will appreciate, thebuilding assemblies can include a variety of other components, includingbut not limited to vapor barriers (e.g., disposed against the sheathingor the wallboard), weather barriers (e.g. a Tyvek™ or other housewrapdisposed against the sheathing), insulation of various materials (e.g.fiberglass, cellulose, foam or stone wool insulations, disposed in spacebetween the framing members), paint or other coatings (e.g., on thesheathing and/or the wallboard(s)) or finishes such as stucco or otherweather resistant materials (e.g. disposed on the sheathing).

Such building assemblies can be prefabricated in a manufacturing processthat is remote from the site where the panel assembly is to beinstalled, then delivered to the site and installed in or on a building.Regardless of whether a building assembly is fabricated on-site oroff-site, any joints between wallboards on a single building assemblycan be finished as described herein before the building assembly isinstalled on or in a building. For example, such joints can be finishedin the manufacturing process to make the building assembly, or in aseparate operation (e.g., at the site but before installation). Whenmultiple such assemblies are installed next to one another to formjoints between wallboards thereof, such joints can be finished in anymanner as described herein.

Certain aspects of the disclosure are now explained further via thefollowing non-limiting examples.

EXAMPLE 1 Surface Roughness Comparison

A joint between wallboards made in accordance with embodiments of thedisclosure was prepared using Easi-Lite Gypsum Board (CertainTeedGypsum, Inc.) as the panel with a sandable coating disposed on thesurface of the panel. The sandable coating was composed of ExtremeAll-Purpose Joint Compound (CertainTeed Gypsum Inc.). The preparedwallboards were then mounted on a support structure forming the jointtherebetween. The joint was then finished using the Extreme All-PurposeJoint Compound and smoothed. Two other joints using alternativewallboards were prepared by the same methods. A first comparison jointwas formed between two Easi-Lite Gypsum Boards that did not include thesandable coating, and the joint was covered with Extreme All-PurposeJoint Compound. A second comparison joint was formed between two RapidDeco® Level 5 (Continental Building Products, Herndon, Va.) boards andwas covered with the corresponding Rapid Deco® Level 5 Joint Compound.Surface roughness measurements were conducted and the differences insurface roughness, both in RMS and Ra values, between the joint and thesurface of the board were determined, as shown in Table 1.

In each of Tables 1 to 3, PP refers to the wallboards including thesandable coating, EL refers to the Easi-Lite Gypsum Boards without thesandable coating, and CRD refers to the Rapid Deco® Level 5 panels. Asshown in Table 1, the difference in surface roughness between the boardwith the sandable coating and the joint was significantly lower than thedifference in the comparison samples.

TABLE 1 Difference between board and joint Rms Ra (μm) Sample (Sq) (Sa)Unit RMS (Sq) Ra (Sa) Unit CRD- 8.9 7.1 μm 2.4 1.9 μm Joint CRD- 6.5 5.1μm x x μm Board EL-Joint 4.0 3.1 μm −8.4 −6.5 μm EL- 12.4 9.6 μm x x μmBoard PP-Joint 3.7 2.9 μm 0.4 0.4 μm PP- 3.3 2.4 μm x x μm Board

Duplicate boards and corresponding joints as described above werepainted and surface roughness measurements were performed. Differencesin roughness between the joint and the surface of the wall panel weredetermined, as shown in Table 2. Again, the samples showed a differencebetween the section covering the board and the section covering thejoint that was significantly lower for the board with sandable coatingapplied to the panel.

TABLE 2 Difference between board and joint Rms Ra (μm) Sample (Sq) (Sa)Unit RMS (Sq) Ra (Sa) Unit CRD- 5.6 4.5 μm −1.5 −1.2 μm Joint CRD- 7.15.7 μm x x μm Board EL-Joint 6.1 4.9 μm −3.1 −2.5 μm EL- 9.3 7.4 μm x xμm Board PP-Joint 5.7 4.4 μm 0.2 0.1 μm PP- 5.5 4.3 μm x x μm Board

EXAMPLE 2 Gloss Comparison

Wallboards and corresponding joints were prepared in the same manner asin Example 1. Gloss was then evaluated at three different locations onthe board using three different measurement angles, as shown in Table 3.The measurements in Table 3 show gloss values for the joint and theboard that were much more similar in value for the sample using theboards with the sandable coating compared to the other samples.

TABLE 3 Joint Board Sample Location 20 60 85 20 60 85 PP 1 1.4 4.7 18.11.4 4.5 25 2 1.4 4.3 18.8 1.4 4.2 24.1 3 1.4 4.2 20.7 1.4 3.9 21.3 avg1.4 4.4 19.2 1.4 4.2 23.5 CRD 1 1.3 2 0.7 1.4 4.7 11.4 2 1.3 2 0.6 1.44.7 11.5 3 1.2 2 0.5 1.4 4.4 10.8 avg 1.3 2.0 0.6 1.4 4.6 11.2 EL 1 1.44.8 26.2 1.2 2.5 0.9 2 1.4 4.4 22.2 1.2 2.5 0.9 3 1.4 4.5 23 1.1 2.5 1.1avg 1.4 4.6 23.8 1.2 2.5 1.0

Various aspects of the disclosure are further described by the followingenumerated embodiments, which can be combined in any number and in anyfashion that is not technically or logically inconsistent.

Embodiment 1. A wallboard comprising: a wall panel including a frontsurface, a rear surface, and opposing first and second side edges; and asandable coating disposed on the front surface of the wall panel.

Embodiment 2. The wallboard according to Embodiment 1, wherein the wallpanel comprises a core having a front surface and a facing disposed onthe front surface of the core, the sandable coating being disposed onthe facing.

Embodiment 3. The wallboard according to Embodiment 2, wherein thefacing is paper.

Embodiment 4. The wallboard according to Embodiment 2, wherein thefacing is a fiberglass mat or a polymer sheet.

Embodiment 5. The wallboard according to Embodiment 1, wherein the wallpanel does not include a facing disposed on a front surface of the core.

Embodiment 6. The wallboard according to any of Embodiments 1-5, whereinthe wall panel has a core formed from a gypsum plaster or astruvite-K/syngenite plaster.

Embodiment 7. The wallboard according to any of Embodiments 1 to 5,wherein the wall panel has a core formed from a material selected fromconcrete, fiber-reinforced materials, foamed polymeric materials such asfoamed polystyrene, mineral board materials, mineral fiber boardmaterials, cellulosic materials, particle board materials, orientedstrand board materials and combinations thereof.

Embodiment 8. The wallboard according to any of Embodiments 1 to 7,wherein the wall panel has at least one tapered portion that extendsfrom a respective one of the side edges.

Embodiment 9. The wallboard according to Embodiment 8, wherein eachtapered portion of the wall panel extends at least 1 inch, e.g., atleast 2 inches, from the respective side edge of the wall panel.

Embodiment 10. The wallboard according to Embodiment 8 or Embodiment 9,wherein each tapered portion of the wall panel extends no more than 5inches, e.g., no more than 3 inches, from the respective side edge ofthe wall panel.

Embodiment 11. The wallboard according to Embodiment 8, wherein eachtapered portion of the wall panel extends in the range of 1 to 5 inchesfrom the respective side edge of the wall panel, for example in therange of 2 to 3 inches.

Embodiment 12. The wallboard according to any of Embodiments 8 to 11,wherein the depth of the taper is in a range of 0.02 inches to 0.25inches from the front surface of the wall panel.

Embodiment 13. The wallboard according to any of Embodiments 1 to 13,wherein the coating includes a main portion that covers a majority ofthe front surface of the wall panel and has a thickness of at least 0.4mm.

Embodiment 14. The wallboard according to Embodiment 13, wherein themain portion has a thickness of no more than 5 mm.

Embodiment 15. The wallboard according to Embodiment 13 or Embodiment14, wherein the coating further includes an area of reduced thickness ina vicinity of at least one of the side edges.

Embodiment 16. The wallboard according to Embodiment 15, wherein thearea of reduced thickness extends at least 1.5 inches from therespective side edge.

Embodiment 17. The wallboard according to Embodiment 15 or Embodiment16, wherein the area of reduced thickness includes a tapered section ofthe coating.

Embodiment 18. The wallboard according to any of Embodiments 15 to 17,wherein the coating includes a smooth transition between the area ofreduced thickness and the main portion.

Embodiment 19. The wallboard according to any of Embodiments 15 to 18,wherein the wall panel includes a tapered portion extending from arespective one of the side edges, and wherein the area of reducedthickness extends to within 1 inch from an inner border of the taperedportion of the wall panel.

Embodiment 20. The wallboard according to any of Embodiments 1 to 19,wherein a coating edge of the coating is set back from a respective sideedge so as to form an uncovered portion of the wall panel between thecoating edge and the respective side edge.

Embodiment 21. The wallboard according to Embodiment 20, wherein theuncovered portion extends at least 1 inch from the side edge.

Embodiment 22. The wallboard according to Embodiment 20 or Embodiment21, wherein the uncovered portion extends no more than 5 inches, e.g. nomore than 3 inches, from the side edge.

Embodiment 23. The wallboard according to Embodiment 20, wherein theuncovered portion extends 1 to 5 inches, for example 2 to 3 inches, fromthe side edge.

Embodiment 24. The wallboard according to Embodiment any of Embodiments1 to 23, wherein the opposing first and second side edges of the wallpanel extend from a first end to a second end of the wall panel, andwherein the coating extends from the first end of the wall panel to thesecond end of the wall panel.

Embodiment 25. The wallboard according to any of Embodiments 1 to 24,wherein the coating includes a highly filled polymer (e.g., ahighly-filled acrylic), a cement-based composition, or a plastercomposition.

Embodiment 26. The wallboard according to any of Embodiments 1-25,wherein the sandable coating includes one or more functional components.

Embodiment 27. The wallboard according to Embodiment 26, wherein the oneor more functional components includes an antimicrobial component or anantimold component, such as a pyrithone salt (e.g., zinc pyrithone,sodium pyrithone), 2-octyl-2H-isothiazol-3-one, carbendazim, terbutryn,3-iodo-2-propynylbutylcarbamate, propiconazole,2-[(thiocyanatomethyl)thio]benzothiazole, 2-(4′-thiazolyl)benzimidazole,10,10′-oxybisphenoxyarsine, N-(fluorodichloromethylthio)phthalimide,N-dimethyl-N′-phenyl-(N′-fluorodichloromethylthio) sulfamide, or diuron.

Embodiment 28. The wallboard according to Embodiment 26 or Embodiment27, wherein the one or more functional components includes aphotocatalyst, e.g., particulate titania (including n-doped titania),zinc oxide, and bismuth-containing materials such as Bi₂O₃, BiVO₄,Bi₂WO₆ and Bi₅O₇I/Bi₂O₃.

Embodiment 29. The wallboard according to any of Embodiments 26-28,wherein the one or more functional components includes a formaldehydescavenger, e.g., alkali metabisulfite, alkali bisulfite, alkali sulfite,alkali thiosulfate, urea, ethyl acetoacetate, carbodiimide compounds, alow mole ratio melamine-urea-formaldehyde resin composition, ormaterials available under the tradename AGOCHEM® SAM.

Embodiment 30. The wallboard according to any of Embodiments 26-29,wherein the one or more functional components includes a fragrance.

Embodiment 31. The wallboard according to any of Embodiments 26-30,wherein the one or more functional components includes an intumescentsystem (e.g., a carbon source such as polyvinylalcohol, pentaerythritolor dierythritol, a blowing agent such as melamine or an HCl-releasingpolymer or additive, and an acid catalyst such as ammoniumpolyphosphate).

Embodiment 32. The wallboard according to any of Embodiments 1 to 31,not disposed on a wall.

Embodiment 33. A building assembly comprising one or more wallboardsaccording to any of Embodiments 1-31.

Embodiment 34. The building assembly according to Embodiment 33, notinstalled on or in a building.

Embodiment 35. A method for installing one or more building assembliesaccording to claim 33, the method comprising providing the one or morebuilding assemblies, and installing them on or in a building.

Embodiment 36. The method according to claim 35, wherein the one or morebuilding assemblies are fabricated remote from the installation site.

Embodiment 37. A system enabling simplified high-quality surfacefinishing of wallboards, the system comprising: at least two wallboardsaccording to any of Embodiments 1 to 32; and a sandable joint compoundconfigurable to cover a joint between the at least two wallboards.

Embodiment 38. The system according to Embodiment 37, wherein acomposition of the coating of the at least two wallboards is the same asa composition of the joint compound.

Embodiment 39. The system according to Embodiment 37 or Embodiment 38,wherein the coating of the wallboards has at least one visualcharacteristic that matches a visual characteristic of the jointcompound.

Embodiment 40. The system according to Embodiment 37, wherein the atleast one visual characteristic includes gloss, and a difference ingloss between the coating and the joint compound is less than 10 glossunits, e.g., less than 5 gloss units, e.g., less than 2 gloss units.

Embodiment 41. The system according to Embodiment 39 or Embodiment 40,wherein the at least one visual characteristic includes surfaceroughness, and a difference between a surface roughness (Ra) of thecoating and a surface roughness (Ra) of the joint compound is no morethan 2 μm, e.g., no more than 0.4 μm, e.g., no more than 0.2 μm.

Embodiment 42. The system according to any of Embodiments 39-41, whereinthe at least one visual characteristic includes color, and a differencebetween a color of the coating and a color of the joint compound has aCIELAB ΔE* value of no more than 3, e.g., no more than 2.3, e.g., nomore than 2, e.g., no more than 1.

Embodiment 43. The system according to any of Embodiments 37-42, whereinthe at least two wallboards are adjacent and form a joint therebetween,and wherein the joint compound covers the joint and a portion of thesandable coating of each of the wallboards.

Embodiment 44. The system according to any of Embodiments 37-43, furthercomprising a coating of paint covering the sandable coating and thesandable joint compound, the coating of paint having a first sectionthat covers the coating on the at least two wallboards and a secondsection that covers the joint compound, and wherein at least one visualcharacteristic of the first section of the coating of paint matches avisual characteristic of the second section of the coating of paint.

Embodiment 45. The system according to Embodiment 44, wherein the atleast one matching visual characteristic of the first and secondsections of the coating of paint includes gloss, and a difference ingloss between the first section and the second section is less than 10gloss units, e.g., less than 5 gloss units, e.g., less than 2 glossunits.

Embodiment 46. The system according to Embodiment 44, wherein the atleast one matching visual characteristic of the first and secondsections of the coating of paint includes surface roughness, and adifference between a surface roughness (Ra) of the first section and asurface roughness (Ra) of the second section is no more than 2 μm, e.g.,no more than 0.2 μm, e.g., no more than 0.1 μm.

Embodiment 47. The system according to Embodiment 44, wherein the atleast one matching visual characteristic of the first and secondsections of the coating of paint includes color, and a differencebetween a color of the first section and a color of the second sectionhas a CIELAB ΔE* value of no more than 3, e.g., no more than 2.3, e.g.,no more than 2, e.g., no more than 1.

Embodiment 48. A method of forming a high quality finish on a wallsurface, the method comprising:

-   -   providing first and second wallboards each according to any of        Embodiments 1 to 35;    -   positioning the first wallboard adjacent to the second wallboard        so as to form a wall surface with a joint between the first and        second wallboards;    -   applying a mass of sandable joint compound over the joint, the        mass of joint compound extending at least from the coating of        the first wallboard to the coating of the second wallboard; and    -   sanding at least a portion of the coating of the first        wallboard, at least a portion of the coating of the second        wallboard, and the joint compound so as to form a high quality        finish on the wall surface.

Embodiment 49. The method according to Embodiment 48, wherein theapplying the mass of joint compound includes:

-   -   applying a first layer of joint compound over the joint;    -   embedding joint reinforcement tape in the first layer of joint        compound;    -   drying the first layer of joint compound with the joint        reinforcement tape embedded therein; and    -   applying a second layer of joint compound over the first layer        of joint compound.

Embodiment 50. The method according to Embodiment 48 or Embodiment 49,wherein the sanding the portion of the coating of the first wallboard,the portion of the coating of the second wallboard, and the jointcompound reduces any protrusion or depression in the wall surface at thejoint to no greater than 2 mm, or to no greater than 1 mm, or to nogreater than 0.5 mm.

Embodiment 51. The method according to any of Embodiments 48 to 50,wherein the applying the mass of joint compound forms a bump over thejoint that projects further outward from the wall surface than thecoatings on the first and second wallboards, and wherein the sanding thejoint compound removes the bump.

Embodiment 52. The method according to any of Embodiments 48 to 51,wherein the positioning the first wallboard adjacent to the secondwallboard includes placing a first side edge of the first wallboardadjacent to a second side edge of the second wallboard.

Embodiment 53. The method according to Embodiment 52 wherein the coatingof the first wallboard includes an area of reduced thickness in avicinity of the first side edge, and wherein the applying the jointcompound covers at least a portion of the area of reduced thickness.

Embodiment 54. The method according to Embodiment 52, wherein thecoating on the first wallboard includes a coating edge in a vicinity ofthe first side edge so as to form an uncovered portion between thecoating edge and the first side edge, and wherein the applying the jointcompound includes using the coating edge as a guide for restricting theapplication of the joint compound on the first wallboard to theuncovered portion of the first wallboard.

Embodiment 55. The method according to any of Embodiments 48 to 54,further comprising, before applying the joint compound, removing aportion of the coating of at least the first wallboard in a vicinity ofthe joint, and wherein the applying the joint compound includes coveringan area where the portion of coating is removed.

Embodiment 56. The method according to Embodiment 55, wherein theportion of coating is removed by sanding.

Embodiment 57. The method according to Embodiment 55 or Embodiment 56

-   -   wherein the opposing first and second side edges of the wall        panel extend from a first end to a second end of the wall panel,    -   wherein the positioning the first wallboard adjacent to the        second wallboard includes placing a first end of the first        wallboard adjacent to a second end of the second wallboard, and    -   wherein the removing a portion of the coating of at least the        first wallboard includes removing coating at the first end of        the first wallboard.

Embodiment 58. The method according to any of embodiments 52-57, whereinthe first wallboard is provided by a first building assembly, and thesecond wallboard is provided by a second building assembly.

Embodiment 59. The method according to embodiment 58, whereinpositioning the first wallboard adjacent to the second wallboard so asto form a wall surface with a joint between the first and secondwallboards comprises positioning the first wallboard adjacent the secondwallboard.

Embodiment 60. A method for making a wallboard according to any ofEmbodiments 1-32, the method comprising providing a wall panel includinga front surface, a rear surface, and opposing first and second sideedges; and forming a sandable coating disposed on the front surface ofthe wall panel.

Embodiment 61. The method according to Embodiment 60, wherein theforming of the sandable coating is not performed at the site where thewallboard is to be installed.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the processes and devicesdescribed here without departing from the scope of the disclosure. Thus,it is intended that the present disclosure cover such modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

What is claimed is:
 1. A wallboard comprising: a wall panel including afront surface, a rear surface, and opposing first and second side edges;and a sandable coating disposed on the front surface of the wall panel.2. The wallboard according to claim 1, wherein the wall panel comprisesa core having a front surface and a facing disposed on the front surfaceof the core, the sandable coating being disposed on the facing.
 3. Thewallboard according to claim 1, wherein the wall panel has at least onetapered portion that extends from a respective one of the side edges,wherein each tapered portion of the wall panel extends at least 1 inch,e.g., at least 2 inches, from the respective side edge of the wallpanel.
 4. The wallboard according to claim 3, wherein each taperedportion of the wall panel extends no more than 5 inches, e.g., no morethan 3 inches, from the respective side edge of the wall panel.
 5. Thewallboard according to claim 4, wherein the depth of the taper is in arange of 0.02 inches to 0.25 inches from the front surface of the wallpanel.
 6. The wallboard according to claim 1, wherein the coatingincludes a main portion that covers a majority of the front surface ofthe wall panel and has a thickness of at least 0.4 mm.
 7. The wallboardaccording to claim 6, wherein the main portion has a thickness of nomore than 5 mm.
 8. The wallboard according to claim 6, wherein thecoating further includes an area of reduced thickness in a vicinity ofat least one of the side edges.
 9. The wallboard according to claim 8,wherein the area of reduced thickness extends at least 1.5 inches fromthe respective side edge.
 10. The wallboard according to claim 8,wherein the coating includes a smooth transition between the area ofreduced thickness and the main portion.
 11. The wallboard according toclaim 8, wherein the wall panel includes a tapered portion extendingfrom a respective one of the side edges, and wherein the area of reducedthickness extends to within 1 inch from an inner border of the taperedportion of the wall panel.
 12. The wallboard according to claim 1,wherein a coating edge of the coating is set back from a respective sideedge so as to form an uncovered portion of the wall panel between thecoating edge and the respective side edge.
 13. The wallboard accordingto claim 1, wherein the coating includes a highly filled polymer (e.g.,a highly-filled acrylic), a cement-based composition, or a plastercomposition.
 14. The wallboard according to claim 1, wherein thesandable coating includes one or more functional components selectedfrom antimicrobial components, antimold components, photocatalysts,formaldehyde scavengers, fragrances, and intumescent systems.
 15. Asystem enabling simplified high-quality surface finishing of wallboards,the system comprising: at least two wallboards according to claim 1; anda sandable joint compound configurable to cover a joint between the atleast two wallboards.
 16. The system according to claim 15, wherein acomposition of the coating of the at least two wallboards is the same asa composition of the joint compound.
 17. The system according to claim15, wherein the coating of the wallboards has at least one visualcharacteristic that matches a visual characteristic of the jointcompound, the at least one visual characteristic comprising one or moreof gloss, wherein a difference in gloss between the coating and thejoint compound is less than 5 gloss units; surface roughness, wherein adifference between a surface roughness (Ra) of the coating and a surfaceroughness (Ra) of the joint compound is no more than 2 μm; and color,wherein a difference between a color of the coating and a color of thejoint compound has a CIELAB ΔE* value of no more than
 3. 18. The systemaccording to claim 15 wherein the at least two wallboards are adjacentand form a joint therebetween, and wherein the joint compound covers thejoint and a portion of the sandable coating of each of the wallboards.19. The system according to claim 15, further comprising a coating ofpaint covering the sandable coating and the sandable joint compound, thecoating of paint having a first section that covers the coating on theat least two wallboards and a second section that covers the jointcompound, and wherein at least one visual characteristic of the firstsection of the coating of paint matches a visual characteristic of thesecond section of the coating of paint.
 20. A method of forming a highquality finish on a wall surface, the method comprising: providing firstand second wallboards each according to claim 1; positioning the firstwallboard adjacent to the second wallboard so as to form a wall surfacewith a joint between the first and second wallboards; applying a mass ofsandable joint compound over the joint, the mass of joint compoundextending at least from the coating of the first wallboard to thecoating of the second wallboard; and sanding at least a portion of thecoating of the first wallboard, at least a portion of the coating of thesecond wallboard, and the joint compound so as to form a high qualityfinish on the wall surface.